Add ability to drop overly large packets

[onak.git] / cleankey.c

diff --git a/cleankey.c b/cleankey.c
index 3ef76f9167679b61316f03f817fd81816ac7437c..fe24c3b6a31a7502de8554ce12bf692b3d18dbb5 100644 (file)
--- a/cleankey.c
+++ b/cleankey.c
@@ -26,7 +26,7 @@
 #include "log.h"
 #include "mem.h"
 #include "merge.h"
-#include "onak-conf.h"
+#include "openpgp.h"
 #include "sigcheck.h"
 
 /**
@@ -179,6 +179,54 @@ int clean_key_sighashes(struct openpgp_publickey *key)
        return removed;
 }
 
+#define UAT_LIMIT      0xFFFF
+#define UID_LIMIT      1024
+#define PACKET_LIMIT   8383            /* Fits in 2 byte packet length */
+int clean_large_packets(struct openpgp_publickey *key)
+{
+       struct openpgp_signedpacket_list **curuid = NULL;
+       struct openpgp_signedpacket_list *tmp = NULL;
+       bool                              drop;
+       int                               dropped = 0;
+
+       log_assert(key != NULL);
+       curuid = &key->uids;
+       while (*curuid != NULL) {
+               drop = false;
+               switch ((*curuid)->packet->tag) {
+               case OPENPGP_PACKET_UID:
+                       if ((*curuid)->packet->length > UID_LIMIT)
+                               drop = true;
+                       break;
+               case OPENPGP_PACKET_UAT:
+                       if ((*curuid)->packet->length > UAT_LIMIT)
+                               drop = true;
+                       break;
+               default:
+                       if ((*curuid)->packet->length > PACKET_LIMIT)
+                               drop = true;
+                       break;
+               }
+
+               if (drop) {
+                       logthing(LOGTHING_INFO,
+                                       "Dropping large (%d) packet, type %d",
+                                       (*curuid)->packet->length,
+                                       (*curuid)->packet->tag);
+                       /* Remove the entire large signed packet list */
+                       tmp = *curuid;
+                       *curuid = (*curuid)->next;
+                       tmp->next = NULL;
+                       free_signedpacket_list(tmp);
+                       dropped++;
+               } else {
+                       curuid = &(*curuid)->next;
+               }
+       }
+
+       return dropped;
+}
+
 /**
  *     cleankeys - Apply all available cleaning options on a list of keys.
  *     @policies: The cleaning policies to apply.
@@ -192,14 +240,17 @@ int clean_key_sighashes(struct openpgp_publickey *key)
 int cleankeys(struct openpgp_publickey **keys, uint64_t policies)
 {
        struct openpgp_publickey *curkey;
-       int changed = 0, count;
+       int changed = 0, count = 0;
 
        if (keys == NULL)
                return 0;
 
        curkey = *keys;
        while (curkey != NULL) {
-               count = dedupuids(curkey);
+               if (policies & ONAK_CLEAN_LARGE_PACKETS) {
+                       count += clean_large_packets(curkey);
+               }
+               count += dedupuids(curkey);
                count += dedupsubkeys(curkey);
                if (policies & ONAK_CLEAN_CHECK_SIGHASH) {
                        count += clean_key_sighashes(curkey);